Rotary printing drum for duplicating machines



R. W. BAILEY Dec. '21, 1954 ROTARY PRINTING DRUM FOR DUFLICATINGMACHINES 4 Shets-Sheet 1 Filed July 21, 1949 INVENOQ" WBAILEY,

Air-702N534 R. W. BAILEY Dec. 21, 1954 ROTARY PRINTING DRUM FORDUPLICATING MACHINES 4 Sheets-Sheet 2 l Filed July 21, .1949

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R. W. BAILEY Dec. 21, 1954 ROTARY PRINTING DRUM FOR DUPLICATING MACHINESFiled July 21, 1949 4 Sheets-Sheet 4 INVENTOR. W 341L553 .QrToQNEY.

United States Patent 2,697,397 Patented Dec. 21, 1954 ROTARY PRINTINGDRUM FOR DUPLICATING MACHINES Richard W. Bailey, Los Angeles, Calif.,assignor to Milo Harding Company, a partnership composed of Milo M.Harding and James M. Harding, Los Angeles, Calif.

Application July 21, 1949, Serial No. 105,942 8 Claims. (Cl. 101-119)This invention relates to duplicating machines, mimeographs and thelike; more particularly, it relates to the rotatable drum commonlyprovided in such machines for mounting the stencil.

It is an object of this invention to provide an improved drum of thistype.

Such drums commonly comprise a perforated cylindrical shell about whichthe stencil is wrapped, a thin layer of porous material such as muslinbeing interposed. Ink within the drum and in contact with the shellfeeds outwardly through the stencil as the drum is rotated, printing aform in accordance with the cutting of the stencil on paper urgedagainst the stencil by passing between the drum and an impressionroller.

It is another object of this invention to provide a duplicator drum orthe like having improved means for supplying ink to the stencil.

It is another object of this invention to provide a duplicator drum orthe like having means for supplying ink to the stencil which willdeliver automaticallya predetermined quantity of ink.

The perforated cylindrical portion of the shell on which the stencil ismounted is usually substantially less than the entire circumference ofthe drum and somewhat less than the length of a stencil. The remainderof the circumference being offset inwardly to accommodate the stencilmounting means etc., exteriorly thereof. As the drum rotates, the ink onthe inner surface of the shell tends to lag behind the movement of theshell, and furthermore is urged outwardly by centrifugal force. Thereduced portion of the shell retards the movement of the ink, so thatthe ink accumulates adjacent the trailing end of the cylindrical shell,the corresponding end of the stencil thus having too much ink while thehead or leading end of the stencil has too little.

It is accordingly another object of this invention to provide aduplicator drum so arranged as to prevent such accumulation of ink.

It is another object of this invention to provide a duplicator drumhaving means to facilitate transfer of ink bletween the opposite ends ofthe cylindrical portion of the s el Conventional stencils forduplicating machines are usually made of such size as to accommodatematter filling a legal size sheet; on the other hand, a large proportionof the matter to be printed is readily accommodated on a letter sizesheet. Thus, there is frequently a space at the lower or trailing end ofthe stencil which is not used. As discussed hereinbefore, the ink tendsto accumulate in the drum shell over this part of the stencil, andfrequently builds up sufiiciently to escape along the opposite edges ofthe stencil, or to cause the stencil to wrinkle, as well as otherdifficulties, partly when this part of the stencil is not cut. It isaccordingly another object of this invention to provide a duplicatordrum or the like arranged to prevent leakage of ink and/or injury to thelower or trailing end of the stencil when printing a letter size form.

It is another object of this invention to provide a duplicator drum orthe like, having optionally operable means for diverting the ink fromthat portion of the drum shell covered by the trailing end of thestencil.

It is another object of this invention to provide a dupli- I cator drumor the like, having optionally operable means for masking that portionof the drum shell covered by the trailing end of the stencil to preventescape of ink through the shell perforations.

The stencil is usually attached to the drum by the aid of a reenforcingmember extending across the head or leading end of the stencil, havinglaterally spaced keyhole shaped openings respectively engaging hook likefingers provided on the drum. The other end of the stencil usually isunattached since the drum rotates in such a direction as to cause thestencil to hug the drum; further, the ink on the porous layer or padcauses the stencil to adhere thereto. In removing a stencil so arranged,it is necessary to grasp the unattached lower or rear end, pull thestencil from the drum, and then unhook it from the fingers. This is anuntidy job due to the ink on the stencil.

It is another object of this invention to provide a dupli- V cator drumhaving stencil mounting means from which the stencil may be removed bymeans of the head or leading end which is free of ink.

It is another object of this invention to provide a duplicator drumhaving means for detachably securing the trailing end of the stencil tothe drum.

It is another object of this invention to provide a dupli cator drumhaving improved means securing the head end of the stencil, optionallyoperable to release the stencil and permit removal thereof.

It is another object of this invention to provide a duplicator drumhaving means for detachably securing the head, as well as the trailingend of the stencil, to the drum.

It is still another object to provide a duplicator drum having novelmounting means for securing it in operative relation with the duplicatorenabling its removal and replacement in a simple and eflicacious manner.

This invention possesses many other advantages and has other objectswhich may be made more easily apparent from a consideration of severalembodiments of the invention. For this purpose there are shown severalforms in the drawings accompanying and forming part of the presentspecification. These forms will now be described in detail, illustratingthe general principles of the invention; but it is to be understood thatthis detailed description is not to be taken in a limiting sense, sincethe scope of the invention is best defined by the appended claims.

In the accompanying drawings:

Figure 1 is a longitudinal sectional view of a duplicating machine,showing in elevation a drum incorporating features of the invention;

Figure 2 is a transverse section on an enlarged scale and partly inelevation, taken substantially as indicated by line 2-2 of Figure 1;

Figure 2-a is a detail section, taken substantially as indicated by line2a-2-a of Figure 2;

Figure 3 is a top plan view, seen as looking down in Figure 2;

Figure 4 is a sectional view, similar to Figure 2, but on a furtherenlarged scale and showing a different operating position of the parts;

Figure 5 is a cross section, taken substantially as indicated by line5-5 of Figure 4;

Figure 6 is a fragmentary section on an enlarged scale, takensubstantially as indicated by line 66 of Figure 5;

Figure 7 is a fragmentary cross section on an enlarged scale, takensubstantially as indicated by line 77 of Figure 3;

Figure 8 is a fragmentary section on an enlarged scale, takensubstantially as indicated by line 88 on Figure 3;

Figure 9 is a fragment of a section similar to Figure 5, but showing amodified form of the invention;

Figure 10 is a view similar to Figure 9 but showing a differentoperating position of the parts;

Figure 11 is a sectional view, similar to Figure 4, but showing anothermodified form of the invention;

Figure 12 is a cross section taken substantially as indicated by line12-12 of Figure 11; and

Figures 13 and 14 are fragmentary sections taken substantially asindicated by the correspondingly numbered lines of Figure 12.

Referring to Figure l, a duplicating machine embodying the presentinvention is shown schematically and comprises a frame generallyindicated by the numeral 1, having upstanding side members 2 and 3 (seealso Figures 2 and 3) which cooperate to support the printing drum 5 forrotation about a horizontal axis 6, the drum being driven in acounterclockwise direction by suitable means (not shown). As shown inFigure 2, the drum 5 has a shell 7 covered in part by an ink pad 8 and astencil sheet 9, a layer of ink (not shown) being provided on the innersurface of the shell 7 for passage through perforations therein to thestencil. Sheets of paper 10 or other suitable material are fed from thestock pile 11 between the drum 5 and the impression roller 12 to beprinted in accordance with the cutting of the stencil, the printedsheets 10 being delivered to the magazine 13.

Referring to Figures 2 to 8, the drum 5 comprises a pair of circularheads and 21 joined in spaced relation by the shell 7. As best shown inFigure 5, the shell has a cylindrical perforated portion 22 which isdiscontinuous, that is, it extends less than a full circumference, theopposite ends thereof being connected by a solid portion 23 spacedradially inwardly from the cylindrical portion 22. The ink pad 8 coversthe perforate portion 22 of the shell 7, the opposite or leading andtrailing ends 8-11 and S-b thereof being anchored in any suitablemanner. Thus, the leading end 8-0 may be attached to a plate 25extending across the drum, by the aid of a hook formed on the plate 25.The plate 25 has a pair of apertures 26, each of which is engaged by amember 27 slidable on the solid shell portion 23 and urged in adirection to tighten the pad 8 by adjustable spring means 29. Theopposite end S-b may be provided with a similar plate which catchesbehind a short extension 22-a of the cylindrical shell portion 22, or asshown in Figure 5 at 30, the end of the pad 8 may be merely folded overthis extension 22-a, since there is very little force acting on the pad.

The stencil 9 is entirely conventional and comprises a paper stiffeneror reenforcing strip 31 at its head or leading end with a plurality ofkey-hole shaped apertures 32 therein, engageable respectively byprojections or fingers 33 formed on a bar 34 extending across the drum 5and supported for angular movement about its axis by reduced portions34-a and 34-h engaging suitable openings in the heads 20 and 21respectively.

The arrangement is such that the bar 34 is oscillatable between aposition in which the fingers or projections 33 are inclined away fromthe stencil as shown in Figure 5, and prevent its removal, and aposition substantially 90" therefrom permitting ready attachment orremoval of a stencil. A light tension spring 35 (Figures 3 and 8) urgesthe bar 34 to stencil retaining position, a short lever 36 beingprovided to facilitate operation of the bar 34 to stencil releasingposition. For this purpose, the arcuate cover plate 37 must first bemoved to permit access to the bar 34, lever 36, etc.. as will bediscussed hereinafter. The lever 36 also serves by means of a lug 36-0engageable with the shell portion 23 to appropriately limit movement ofthe bar 34 by spring 35.

The opposite or trailing end of the stencil 9 is also secured to thedrum 5. Thus, as shown in Figure 5, the length of the stencil sheet 9 issuch that the sheet extends beyond the extension 22-a and along theshell portion 23. An elongated member 40 extending across the drum 5 hasa forward edge 40-0 adapted to engage the stencil 9 immediately adjacentthe extension 22-0 for this purpose being rotatably mounted on the bar41 by the aid of webs 40-h. A pair of tension springs 42 anchored at 43on the shell portion 23 (see Figure 7) and connected to a flange 40-1:on the member 40 urge the member 40 about the bar 41 so that theedgeAO-a presses against the stencil 9. For moving the member 40 intoand out of engagement with the stencil, bar 41 is pivotally mounted inthe heads 20 and 21 by offset pintles 44 and 45, one of which, as 45,extends through the head 21 and has an operating knob 47 securedthereon.

As clearly shown in Figures 5 and 7, the pintles 44 and are so locatedwith respect to the points of attachment of the springs 42 as to form anover center arrangement wherein the member 40 in either stencil engagingposition or releasing position is urged about the bar 41 by the springs42 in a clockwise direction. Thus, in stencil engaging position, theforward edge 40-11 of the member 40 clamps the trailing end of thestencil 9 against the shell portion 23, and in stencil releasingposition engages the shell portion 23 at a point spaced from saidstencil end, thereby releasably maintaining the member 40 againstmovement.

.The foregoing manner of mounting the stencil 9 enables removal of thehead end of the stencil first, an important advantage since this end hasthe reenforcing piece 25 and is free of ink. However, if desired, thestencil 9 may be removed in conventional manner by operating theglamping member 40 to release the trailing or rear end rst.

The arcuate plate 37 is provided to form a protection cover for the headof the stencil 9 and the anchoring means therefor, being mounted formovement about the axis of the drum 5 between a closed position coveringsaid head and stencil means and an open position in which they areexposed for manipulation. For this purpose, the opposite edges of theplate 37 are slidingly accommodated respectively in grooves 50 and 51 inthe heads 20 and 21. A latch member 53 (Figure 7) is pivotally mountedon the inside of the plate 37 by the aid of cars 54, being urged by aspring 55 so that its inner end 53-a normally engages the shell portion23. The opposite end of the member 53 has a thumb button 53-b thereonaccommodated in an opening 37-a in the plate 37. The inner end 53-(! ofthe member 53 by engaging a stop lug 56 on the shell portion 23, servesto releasably maintain the plate 37 in closed position. Pressure on thethumb button 53-h disengages the member 53 from the lug 56, so that theplate 37 may be moved to open position.

The ink for the stencil is supplied to the interior of the drum 5through an opening 60 in the shell portion 23, closed by a threaded plug61. With the advent of thinner quick drying inks, it is important thatthe amount of ink in the shell is not excessive; further it isadvantageous to be able to replenish the ink supply in an appropriateamount and without the need of removing the plug 61 every time.

Accordingly, means are provided for containing a body of ink in the drum5 substantially in excess of the amount for use by the stencil, meansoperable from the exterior of the drum being provided for releasing theink in appropriate predetermined amounts.

For containing the body of ink, a stationary cradle 62 is rotatablysupported within the drum 5 by the aid of a tubular member 63 extendingaxially of the drum. The cradle 62 comprises an arcuate bottom formingplate 64 concentric with the perforated shell 22 spaced inwardlytherefrom and supported by upright end plates 65 and 66 having hubs 65-aand 66-11 which engage the tubular member or axle 63. A tie plate 67extends between the upper ends of the plates 65 and 66.

The cradle 62 has an elongated opening 68 in the bottom plate 64, aswell as an intermediate plate 69 with a similar opening or aperture 70,providing first and second or upper and lower ink containing chambers 71and 72. A closure member 73 is suspended between the bottom 64 and theintermediate plate 69 by a pivotedlink '74 connected to one arm of alever member 75 rockably supported between upstanding ears formed on theopposite edges of the bottom plate 64, one of such ears being indicatedat 76, Figures 2 and 4. As clearly shown in Figures 4 and 5, the closuremember 73 comprises a metal plate 73-a of such size as to overlie theopenings 68 or and connected to link 74 by the aid of lug 73-b. Aresilient pad 78 is provided on the upper face of plate 73-51 forsealing about the aperture 70 when the closure 73 is in its upperposition. A similar pad 79 is provided on the lower face of the plate73-11 for sealing about the opening 68 when the closure 73 is in itslower position, this pad 79 however being somewhat thicker to allow forthe curvature of the bottom plate 64.

The arrangement is such that the closure 73 normally closes the bottomopening 68, the aperture 70 being open, so that the ink chambers 71 and72 are in free communication but no ink can pass onto the interiorsurface of the drum 5. However, the closure 73 is optionally operable touncover the bottom opening 68 and close the aperture 70, thus allowingthe ink in the lower chamber 72 to flow onto the interior drum surface.Thus, by making the lower chamber 72 of appropriate size, apredetermined amount of ink is delivered at each operation of theclosure 73. After the ink has been released from the lower chamber 72,the closure 73 is returned to its normal position, closing the opening63 and opening the aperture 70. allowing the lower chamber 72 to refillfrom the upper ch mber 71. To f cilitate the emptying and filling of t elower chamber 72. appropriate air vents 77 are provided at each endthereof.

For operating the lever a sleeve 80 is rotatably and slidably mounted onthe axial member 63 and has a notched lug 80-a engaging a notch 75-!) inarm 75-a of the lever 75. This prevents rotation of the sleeve 80 aswell as constraining the lever 75 to swing in accordance with the axialmovement of the sleeve 80, a compression spring 81 confined between thesleeve 80 and the end boss 65a, normally maintaining the parts withclosure 73 closing the bottom opening 68.

For moving the sleeve 80 to cause the closure 73 to move to its otheroperating position, a push rod 82 is slidably mounted in the member 63extending inwardly from one end and having a transverse pin 83 adjacentits inner end projecting through oppositely disposed slots 63a in themember 63. Rollers 84 are provided on the pin 83 for engaging the sleeve80, since the push rod 82 and pin 83 rotate with the member 63, whilethe sleeve 80 remains stationary. The outer end of the rod 82 has aslightly enlarged head 82-a which is sealed against the bore in member63 as by a conventional O-ring 85 accommodated in a groove in the head82-a.

The opposite end of the member 63 has an elongated plug 86 securedtherein with a through axial opening 86a to be more fully discussedshortly. A compression spring 88 confined between the plug 86 and rod 82urges the rod 82 outwardly, pin 83 by engagement with the ends of slots63a serving to limit such movement. Means to be discussed hereinafterare provided for urging the rod 82 inwardly to operate the closure 73.

It will be obvious that the closure 73 must not dwell at an intermediatepoint with both openings 68 and 70 simultaneously uncovered, since thiswould prevent proper metering of the ink delivered to the interior ofthe drum 5. To insure proper operation of the closure 73, it iscontinually biased by the spring 81 to close the lower opening 68, thisforce being supplemented by that of a leaf spring 89 confined betweenarm 75-0 of the lever 75 and the end plate 65. This spring 89 isarranged in a known man er to exert a force opposing movement of thelever 75 from either limiting position and which increases as the leverreaches an intermediate position. Thus, while the force of spring 81overrides the force of spring 89, exertion of a force on the lever 75sufficient to move it from a position in which the closure 73 closes theopening 68 to and through an intermediate position, will insure furthermovement of the lever 75 in response to ri 89 s th t the closure 73 clses the aperture 70.

The drum 5 is mounted in the duplicator by the aid of the conical hubs90 and 91 secured respectively to the drum heads and 21, hub 90 beingsecured by a special screw 92 threaded into the plug 86. The hubs 90 and91 respectively engage members 94 and 95 providing conical cups forreceiving the conical surfaces of the hubs 90 and 91, and rotatablysupported by the upstanding side members 2 and 3 of the frame 1. One ofthese cup members, as 94, may be power driven, the drum 5 being indriving relation therewith by a pin 96 in the head 20 engaging slot 94-ain the cup member 94.

The screw 92 has a central aperture leading from the aperture 86-0 inthe plug 86 to the space between the hub 90 and cup 94 (see Figure 2),communication between this space and the atmosphere being provided byone or more transverse grooves 90a in the surface of the hub 90. Theaperture 86-01 opens into the interior of the member 63 whichcommunicates freely with the interior of drum 5 by ports 63-11. In thisway, atmospheric pressure within the drum is assured at all times.

The other cup member 95 is rotatably mounted on'the inner end of a shorthollow shaft 97, but is restrained against axial movement thereon, andmay be optionally driven by means independent of the means driving themember 94, such as a hand crank (not shown) for rotating the drum 5. Forthis purpose the member 95 includes an integral spur gear 95-0: and adriving pin 98 is provided in the head 21 engaging a slot 954: in themember 95.

The shaft 97 is supported for angular and axial movement in the frameupright 3 by means of a bushing 100 fixed therein, a knob 101 beingsecured on the outer end of shaft 97 to facilitate its operation.Appropriate movement of the shaft 97 and member 95 thereon to the left(Figure 2) will disengage the member 95 from the hub 91 and allow thedrum 5 to be moved to the left to disengage the hub 90 from the othercup 94, freeing the drum 5 for removal from between the uprights 2 and3. Similarly, movement of the shaft 97 and member 95 to the right willsecure the drum 5 after it is replaced.

The shaft 97 is resiliently urged to drum retaining positil tion by adetent arm 102 pivotally mounted at 102-a on a plate 103 secured withinthe upright 3 about the shaft (Figures 2 and 2-a). The arm 102 inclinesfrom the end 102-11, away from the plate 103 to the free end which isurged inwardly or toward the drum 5 by a compression spring 104, therebeing a recess 102-b adjacent the free end normally engaged by a pin 105projecting from the shaft 97. The spring 104 thus serves to maintain thedrum 5 in operating position by urging the cups 94. and 95 and theirrespective hubs into engagement.

When it is desired to remove the drum, the operator, by means of theknob 101 exerts suflicient turning force in a counterclockwisedirection, referring to Figure 2-a, on shaft 97, to force the pin 105out of the recess 102-b, the shaft 97 then being rotated about to alignpin 105 with a slot 106 extending through the plate 103 and axially inbushing 100. The shaft 97 together with the cup member is then movedaxially t0 the left to disengage the member 95 and hub 91. Inward andclockwise movement of the shaft 97 will cause engagement of pin anddetent notch 102b, thus locking drum 5 in place.

An operating rod 107 for actuating the ink feeding mechanism is slidablein the bore of the hollow shaft 97, having a head 107-a projecting fromthe knob 101 and confining a spring 108 against the end of the shaft 97.The spring 108 urges the rod 107 outwardly, a suitable stop member 107-bon the rod 107 limiting such movement by contact with the inner end ofthe shaft 97. The inner end of rod 107 is adapted to contact push rod 82so that suitable pressure exerted on the head 107-a will actuate theclosure 73 in the manner previously discussed.

The rotation of the drum 5 causes the ink on the inner surface of thecylindrical shell portion 22 to accumulate adjacent the trailing end ofthe shell 22 where it joins the inwardly spaced shell portion 23. Thisis objectionable in any case since it results in an excessive ink supplyfor the trailing end of the stencil and especially since the lastseveral inches of the stencil are not cut or used in a large proportionof the work. Accordingly, means are provided optionally operable formasking this portion of the shell 22.

Thus, as shown in Figures 4 and 5, a plate 110 is provided extendingbetween the heads 20 and 21 and in spaced relation over the trailing endof the shell portion 22 and the adjacent end of the inwardly spacedshell portion 23. At the leading end of the plate 110, a control flap111 is provided, secured on a bar 112 extending longitudinally of thedrum 5 and rotatably mounted at its opposite ends in the drum heads 20and 21 respectively. Bar 112 projects through the head 21 having anoperating knob 113 secured on its outer end.

The arrangement is such that the flap 111 may be positioned as indicatedby full lines to prevent entry of ink between the shell 22 and themasking plate 110 or as indicated by the broken lines to permit ink toenter freely. However, it is to be noted that in the latter case thethickness of the ink layer acting on the trailing end of the shell 22and the stencil 9 can never exceed the distance by which the maskingplate 110 is separated from the shell. As shown in Figure 6, a springpressed ball 114 maybe provided in the head 21 engageable with either ofa pair of recesses 115 in the knob 113 for retaining the flap 111 inadjusted position, appropriate indicia 116 (Figure 1) being provided onthe head 21 cooperating with a mark on the knob 113 to indicate theposition of the flap 112.

A modified form of means for masking the trailing end of the cylindricalshell portion is shown in Figures 9 and 10. Therein an arcuate plate119, adapted to closely engage the inner surface of the shell 22, issupported for swinging movement into and out of contact with the shellby a plurality of longitudinally spaced arms such as indicated by 120pivoted respectively to lugs 121 on the inside of the shell portion 23.A longitudinally extending shaft 122 is rotatably supported at itsopposite ends in the heads 20 and 21 respectively, an operating knob 123being provided on one end thereof as before.

One or more springs 124 tensioned between the shaft 122 and lugs 119-aon the plate 119, urge the plate inwardly of the shell 22, such movementbeing opposed by the engagement of a cam surface 119b with projectingcam means 122a on the shaft 122, as shown in Figure 9. Upon rotation ofthe shaft 122 to disengage the cam 122-a and the cam surface 119-b, theplate 119 swings inwardly against shaft 122 as a stop, allowing freepassage of ink over the trailing end of the shell 22 (Figure 10).Reverse 7 shaft 122 reengages the cam 122-a and cam surface 119-b andreturns the plate 119 to its masking position, an extension 119-c of thecam surface 119-b serving as a stop to appropriately limit rotation ofthe shaft 122 by engaging the cam 122-a.

In Figures 11 and 12 a modified form of ink cradle is shown inconnection with a modified form of printing drum, but it is to beunderstood that there is no especial cooperation between these modifiedforms, as'the drum of Figure ll could as well employ the ink cradle ofFigures 2 to 5, and the drum of Figure 2 et seq. could equally as wellemploy the ink cradle of Figures ll and 12.

Referring to Figures 11 and 12, the printing drum shown therein isgenerally quite similar to the previously described drum comprisingcircular heads 130 and 131 joined by a shell having a discontinuouscylindrical perforated portion 132' with its ends joined by an inwardlyspaced portion 133.

However, to prevent the previously discussed accumulation of inkadjacent the trailing end of the cylindrical shell portion 132, a pairof channels 134 and 135 are provided in the inwardly spaced shellportion 133 connecting said trailing end with the leading end of thisportion 132. Thus, the width of the shell portion 133 is less than thespace between the heads 130 and 131 so that the opposite edges thereofare spaced from the heads, means 136 and 137 being provided adjacent theheads 130 and 131 respectively forming narrow continuations of thecylindrical shell portion 132 connecting its opposite ends. The means136 and 137 are connected at their outer edges respectively to the heads130 and 131 and at their inner edges by upstanding walls 138 and 139 tothe shell portion 133. It will be apparent that ink accumulationadjacent the trailing end of the cylindrical shell portion 132 will flowlongitudinally along the shell to the channels 134 and 135 and thencevia the channels to the leading end of the shell portion 132. Sincethese channels 134- and 135 form a continuation of the cylindrical shellportion 132, free flow of the ink results.

The described arrangement has important advantages in providing auniform distribution of ink over the stencil, avoiding excessive inkingof the trailing end of the. stencil whil assuming an ample supply of inkfor the head end.

The inking pad 8 and the stencil 9 may be secured to the drum insubstantially the same manner as in the first described form of theinvention. However, as shown in Figure 13, the anchoring means 140 forthe trailing end of the stencil 9, similar to that previously described,is rotatably supported by engagement of the pintles 140-a and 14041 withthe channel walls 138 and 139 respectively, pintle 1411-17 extendingacross the channel 135 and through the head 131, an operating knob 1 i1being fixed on its outer end. Likewise one end of the anchoring bar 142for the head of the stencil 9, similar to that previously described, isrotatably supported by the channel wall 139 as shown in Figure l4,theother end being similarly supported by the channel wall 133.

An arcuate protective cover 143 is provided as before, slidably mountedin grooves 14-4 and 145 defined respectively by the channel bottoms 136and 137 and flanges 146 and 147 on the heads 130 and 131.

The stationary cradle 15% for containing the ink is generally quitesimilar to that of the first described form or the invention andcomprises an arcuate bottom wall 151 with an elongated opening 152 andan intermediate apertured wall 153 with an opening 154, a closure member155 similar to that of the first described form of the invention beingprovided for controlling the openings. The cradle 150 is rotatablysupported with respect to the drum by end plates 156 and 157 secured tohubs 158 and 159 and braced by a top spacer plate 161. This plate 161has an opening 161-5: for facilitating the passage of ink from the drumopening 162.

The hub 15% is rotatably mounted on a tube 163 fixed in the head 13) andextending inwardly therefrom to provide an air vent for the interior ofthe drum, a protective cover 164 being provided to prevent accidentalentry of ink into the tube 163. The other hub 159 is rotatably supportedon the axially extending push rod 165 which operates the closure 155.

A lever member 166 is rockably mounted on the spacer plate 161 by theaid of a bracket 167 and is con nected to the closure by a link 168. Thelever member rotation of the 166 has a crank-like lateral extension 169with a slot 169a for accommodating a reduced neck -a on the push rod165. The push rod 165 has a packed head 165b at its outer end slidablein a bore 170 provided in the drum head 131, a spring 171 confinedbetween the head 165-b and hub 159 urging the push rod 165 outwardly, tocause the closure 155 to close the bottom opening 152. Appropriatepressure exerted on the push rod 165, as by the operating rod 107 willcause the closure 155 to uncover the bottom opening 152 and close theaperture 154, thus delivering a metered quantity of ink as determined bythe volume defined betwen the cradle bottom 151 and the plate 153. Uponrelease of the push rod 165, the closure 155 returns to its normalposition closing the bottom opening 152. A flat spring 172 engages anextension 166-11 of the lever 166 for insuring movement thereof toinsure movement of the closure 155 to close either of the openings 152or 154, in a manner similar to that in the first described form of theinvention.

As in the first described form of the invention, it may be desirable toprovide optionally operable means for masking the trailing end portionof the shell portion 132, for which purpose, an arrangementsubstantially identical with that disclosed in Figures 9 and 10 isshown. Thus, an arcuate plate 179 adapted to closely engage the innersurface of shell 132, and corresponding with plate 119 of Figures 9 and10, is supported for angular movement toward and away from shell 13?. bya pair of arms 180, and is optionally movable into and out of maskingposition by the aid of a rotatable cam shaft 182 and tension spring 184all as before.

1 claim:

l. In a. rotatable printing drum for a duplicating machine: a perforateshell adapted to have a stencil sheet secured on its exterior; astationary cradle rotatably suspended within the drum; said cradleincluding a horizontal, wall forming upper and lower ink containingchambers in said cradle, there being an opening through said wall forestablishing communication between said chambers as well as an openingthrough the bottom of said cradle for discharging ink into the interiorof said shell; a closure adapted to close either of said openings; meansincluding an element extending axially of said drum for operating saidclosure; means urging said closure to close the opening in said cradle;and means efiective upon movement of said closure to open said cradleopening exerting a force urging said closure to close the opening insaid wall.

2. In a printing drum for a duplicating machine: a perforate shelladapted to have a stencil sheet secured on its exterior; meanssupporting said drum for rotation about its axis and providing anaxially extending opening at each end of the drum; a stationary cradlefor containing a body of ink, means suspending said cradle in said drum,including opposed members mounted in the openings at the ends of thedrum, there being an opening in the bottom of said cradle to pass ink tothe interior of the shell; a closure for said opening normally closingsaid opening; one of said members being slidably supported in theopening in one end of the drum, means responsive to sliding of said onemember for operating said closure to open, the other of said membersproviding a clear passage between the interior and exterior of the drum.

3. In a printing drum for a duplicating machine: a perforate shelladapted to have a stencil sheet secured on its exterior; meanssupporting said drum for rotation about its axis, a tubular memberextending axially through said drum; a cradle suspended from said memberwithin said drum for containing a body of ink, there being an opening insaid cradle to pass ink to the interior of the shell; a closure for saidopening: lever means pivoted on said cradle for operating said closureto open and to close; a first element slidable on said member andconnected to operate said lever; a second element slidable within saidmember; means movable exteriorly of said member responsive to sliding ofsaid second element for engaging and sliding said first element tooperate said lever in closure opening direction; and spring means urgingsaid first element to operate said lever in closure closing direction.

4. In a printing drum for a duplicating machine: a perforate shelladapted to have a stencil sheet secured on its exterior; meanssupporting said drum for rotation about its axis and providing anaxially extending opening, fixed to said drum; a stationary cradlerotatably suspended from said means within said drum for containing abody of ink, there being an opening in said cradle to pass ink to theinterior of the shell; an apertured wall in said cradle spaced above thebottom thereof to form upper and lower ink containing chambers; aclosure adapted to close either said opening or the aperture in saidWall; lever means pivoted on the cradle for operating said closure; anelement slidably supported by said means connected to said lever means;spring means urging said element to move said closure in a direction toclose said opening; an element axially movable in said axially extendingopening for operating said slidable element in a direction to open saidopening and close the aperture in said wall; and a resilient elementinterposed between said lever means and said cradle opposing movement ofsaid lever means in a direction to move said closure from either closedposition.

5. In a printing drum for a duplicating machine: a perforate shelladapted to have a stencil sheet secured on its exterior; meanssupporting said drum for rotation about its axis a tubular member fixedto said drum; a cradle suspended from said tubular member within saiddrum for containing a body of ink, there being an opening in said cradleto pass ink to the interior of the shell; a closure for said openingnormally urged to closed position; a lever pivoted on said cradle, meansconnecting said lever with said closure for operating said closure toopen and to close responsive to movement of said lever; an elementaxially movable in said tubular member; a sleeve mounted to slide on theexterior of said tubular member; means operatively connecting saidsleeve with said lever; and means movable axially of said tubular memberfor engaging and sliding said sleeve responsive to axial movement ofsaid element.

6. In a printing drum for a duplicating machine: a perforate shelladapted to have a stencil sheet secured on its exterior; meanssupporting said drum for rotation about its axis including a pair ofmembers respectively at opposite ends of the drum, at least one of saidmembers having an axially extending opening into the drum; a stationarycradle rotatably supported by said members within said drum forcontaining a body of ink; a wall in said cradle spaced above the bottomthereof, and forming upper and lower ink containing chambers; therebeing an opening in said Wall for establishing communication betweensaid chambers, as well as a discharge opening in the bottom chamber; acommon closure movable between positions closing one or the other ofsaid openings; means biasing said closure to close one of said openings;and means slidable in said axially extending opening for optionallyoperating said closure to open said one opening and to close the otheropenlng.

7. inking apparatus for the rotary printing drum of a duplicatingmachine, comprising; a cradle for consliding movement relative thereto,

taining a supply of ink, a mounting member for suspending the cradletherefrom in the drum, adapted to rotate with the drum relative to thecradle; said cradle having an opening for passing ink into the drum, aclosure for said opening, an operating member mounted on said mountingmember for rotation therewith and adapted to be operated from theexterior of the drum; a second member mounted on said supporting memberfor sliding movement relative thereto, means for moving said secondmember relative to said supporting member responsive to sliding movementof said operating member, means connecting said second member with saidclosure for moving the closure to open and close, responsive to movementof said second member, and spring means urging said last named means toclose said opening.

8. Inking apparatus adapted to be mounted in the rotary printing drum ofa duplicating machine; comprising: a cradle adapted to contain ink,having an opening for passing ink onto the interior of the drum, meansfor mounting the cradle Within the drum, including a tubular membersuspending the cradle therefrom and adapted to rotate relative theretoupon rotation of the drum, a closure for said opening, a slidable memberin said tubular member operable from the exterior of said drum; saidtubular member having a slot therein, a sleeve surrounding said tubularmember for sliding movement thereon, a projection on said slidablemember extending through said slot and contacting said sleeve, wherebysliding movement of said slidable member causes corresponding movementof said sleeve, means connecting said sleeve with said closure formoving said closure responsive to sliding movement of said sleeve, andsprings on said tubular member urging said slidable member and saidsleeve in a direction for holding said closure in position to close saidopening.

References Cited in the file of this patent UNITED STATES PATENTS NumberName Date 628,651 Cummings July 11, 1899 658,037 Dick Sept. 18, 1900976,704 Smith Nov. 22, 1910 1,095,275 Gibbs et al. May 5, 1914 1,215,310McCrea Feb. 6, 1917 1,527,783 Brasseur Feb. 24, 1925 1,597,250 RowleyAug. 24, 1926 1,607,386 Brasseur Nov. 16, 1926 1,625,054 Rosato Apr. 19,1927 1,687,003 Brasseur Oct. 9, 1928 1,928,233 Simonsen Sept. 26, 19332,092,242 Brasseur Sept. 7, 1937 2,169,933 Terrier et al Aug. 15, 19392,307,291 Packwood Jan. 5, 1943

